For years, the poster child of the anti-open source movement was Microsoft, with its proprietary software model. In recent years, however, the company has changed its views, starting an open source software lab to work on interoperability issues. It's even become a purveyor of its own open source-approved licenses.

What do these efforts mean? For Sam Ramji, Microsoft's director of open source technology strategy, they indicate the company is "open" for business.

"The strategy is founded on meeting people where they are," Ramji told InternetNews.com. "Independent of whether or not the application programming layer is a Microsoft technology, we really look at ourselves as being an infrastructure layer, and our job is to support the workload and the development styles that people want to use."

"Our goals first and foremost were looking for performance parity with Linux for PHP workloads," Ramji said. "This is putting our best efforts into PHP."

Beyond just making key open source technologies such as PHP run well on its platforms, Microsoft is also bringing new open source skills into the company itself. Crispin Cowan, a key developer behind Novell's AppArmor Linux security effort, is among Microsoft's recent open source hires.

Ramji also said Tom Hanrahan now leads the Linux interoperability work in Microsoft's Open Source Lab. Prior to joining Microsoft, Hanrahan had been the director of Linux engineering at the Open Source Development Labs, or OSDL, as it's more commonly known.

"People talk about bringing in new blood, and we need to have the people that embody the practices we hope the company to have," Ramji said. "If you want to execute change, you need to have change agents."

Ramji is also optimistic about Microsoft's Open Source code efforts with the Microsoft Public License (known as Ms-PL) and the Microsoft Reciprocal License (or Ms-RL), which have been officially approved by the nonprofit Open Source Initiative (OSI) since October.

"I'm humbled and grateful to the OSI for approving the licenses," Ramji said. "It cements their moral authority and shows some optimism that we can bring our models together."

Since gaining OSI approval, Ramji said Microsoft's CodePlex open source code development effort has undertaken 30 new projects. In total, there are now 190 projects on CodePlex using either the Ms-PL or Ms-RL.

Though Ramji sees positive momentum for open source at Microsoft, he also sees many challenges lie ahead. Among them is helping others at Microsoft determine when and where open source makes sense.

He says that effort will entail figuring out what part of a product needs to be open source and modifiable, as well as which part needs to be visible and understandable for debugging purposes -- but not changeable.

In addition, Ramji says, the company needs to decide what should remain closed source, not visible and only modifiable by Microsoft's own developers.

"We're conducting internal briefings and training sessions on what are the policies and how do you think through the legal implications," Ramji said. "The other component is working with product groups on how you go to market and the revenue model."

"At the end of the day, for this to be sustainable for any company, there has to be a consistent way that additional effort produces additional revenue," he adds.